Problem: Daniel ate 1 slice of pizza. Christopher ate 2 slices. If Daniel ate $\dfrac{1}{6}$ of the pizza, what fraction of the pizza was eaten?
Explanation: If 1 slice represents $\dfrac{1}{6}$ of the pizza, there must have been a total of 6 slices. $\text{fraction of pizza eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ They ate ${3}$ out of $6$ slices. They ate $\dfrac{3}{6}$ of the pizza.